Thermal chemistry of bicyclo[4.2.0]oct-2-enes. Academic Article uri icon

abstract

  • At 300 degrees C, bicyclo[4.2.0]oct-2-ene (1) isomerizes to bicyclo[2.2.2]oct-2-ene (2) via a formal [1,3] sigmatropic carbon migration. Deuterium labels at C7 and C8 were employed to probe for two-centered stereomutation resulting from C1-C6 cleavage and for one-centered stereomutation resulting from C1-C8 cleavage, respectively. In addition, deuterium labeling allowed for the elucidation of the stereochemical preference of the [1,3] migration of 1 to 2. The two possible [1,3] carbon shift outcomes reflect a slight preference for migration with inversion rather than retention of stereochemistry; the si/sr product ratio is approximately 1.4. One-centered stereomutation is the dominant process in the thermal manifold of 1, with lesser amounts of fragmentation and [1,3] carbon migration processes being observed. All of these observations are consistent with a long-lived, conformationally promiscuous diradical intermediate.

published proceedings

  • J Org Chem

altmetric score

  • 3

author list (cited authors)

  • Powers, D. C., Leber, P. A., Gallagher, S. S., Higgs, A. T., McCullough, L. A., & Baldwin, J. E.

citation count

  • 12

complete list of authors

  • Powers, David C||Leber, Phyllis A||Gallagher, Sarah S||Higgs, Andrew T||McCullough, Lynne A||Baldwin, John E

publication date

  • January 2007